CentOS ProjectGENCORE_ADVISORY.ASCVulnerability in gencore affects AIX,Vulnerability in gencore affects VIOS
CVSS2
Attack Vector
LOCAL
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:L/AC:L/Au:N/C:N/I:P/A:N
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
HIGH
Availability Impact
NONE
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
EPSS
Percentile
5.1%
IBM SECURITY ADVISORY
First Issued: Tue Jan 19 16:15:13 CST 2021
|Updated: Tue Mar 30 09:09:39 CDT 2021
|Update: iFix now provided for AIX 7200-04-03 and VIOS 3.1.1.30.
The most recent version of this document is available here:
http://aix.software.ibm.com/aix/efixes/security/gencore_advisory.asc
https://aix.software.ibm.com/aix/efixes/security/gencore_advisory.asc
ftp://aix.software.ibm.com/aix/efixes/security/gencore_advisory.asc
Security Bulletin: Vulnerability in gencore affects AIX (CVE-2020-4887)
===============================================================================
SUMMARY:
There is a vulnerability in the gencore user command that affects AIX.
===============================================================================
VULNERABILITY DETAILS:
CVEID: CVE-2020-4887
https://vulners.com/cve/CVE-2020-4887
https://vulners.com/cve/CVE-2020-4887
DESCRIPTION: The AIX gencore user command may be exploited to create
arbitrary files in any directory.
CVSS Base Score: 6.2
CVSS Temporal Score: See
https://exchange.xforce.ibmcloud.com/vulnerabilities/190911
for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N)
AFFECTED PRODUCTS AND VERSIONS:
AIX 7.1, 7.2
VIOS 3.1
The vulnerabilities in the following filesets are being addressed:
key_fileset = aix
Fileset Lower Level Upper Level KEY
---------------------------------------------------------
bos.mp64 7.1.5.0 7.1.5.40 key_w_fs
bos.mp64 7.2.3.0 7.2.3.19 key_w_fs
| bos.mp64 7.2.4.0 7.2.4.7 key_w_fs
bos.mp64 7.2.5.0 7.2.5.1 key_w_fs
To find out whether the affected filesets are installed
on your systems, refer to the lslpp command found in AIX user's guide.
Example: lslpp -L | grep -i bos.mp64
REMEDIATION:
A. APARS
IBM has assigned the following APARs to this problem:
AIX Level APAR Availability SP KEY
-----------------------------------------------------
7.1.5 IJ28825 ** SP08 key_w_apar
7.2.3 IJ28826 ** SP07 key_w_apar
7.2.4 IJ28827 ** SP04 key_w_apar
7.2.5 IJ28828 ** SP02 key_w_apar
VIOS Level APAR Availability SP KEY
----------------------------------------------------
3.1.0 IJ28826 ** 3.1.0.60 key_w_apar
3.1.1 IJ28827 ** 3.1.1.40 key_w_apar
3.1.2 IJ28828 ** 3.1.2.20 key_w_apar
Subscribe to the APARs here:
http://www.ibm.com/support/pages/apar/IJ28825
http://www.ibm.com/support/pages/apar/IJ28826
http://www.ibm.com/support/pages/apar/IJ28827
http://www.ibm.com/support/pages/apar/IJ28828
https://www.ibm.com/support/pages/apar/IJ28825
https://www.ibm.com/support/pages/apar/IJ28826
https://www.ibm.com/support/pages/apar/IJ28827
https://www.ibm.com/support/pages/apar/IJ28828
By subscribing, you will receive periodic email alerting you
to the status of the APAR, and a link to download the fix once
it becomes available.
B. FIXES
AIX and VIOS fixes are available.
An LPAR system reboot is required to complete the iFix installation,
or Live Update may be used on AIX 7.2 to avoid a reboot.
The AIX and VIOS fixes can be downloaded via ftp or http from:
ftp://aix.software.ibm.com/aix/efixes/security/gencore_fix.tar
http://aix.software.ibm.com/aix/efixes/security/gencore_fix.tar
https://aix.software.ibm.com/aix/efixes/security/gencore_fix.tar
The link above is to a tar file containing this signed
advisory, fix packages, and OpenSSL signatures for each package.
The fixes below include prerequisite checking. This will
enforce the correct mapping between the fixes and AIX
Technology Levels.
AIX Level Interim Fix (*.Z) KEY
----------------------------------------------
7.1.5.5 IJ28825m5a.201221.epkg.Z key_w_fix
7.1.5.5 IJ28825m5b.201221.epkg.Z key_w_fix
7.1.5.6 IJ28825m6a.201221.epkg.Z key_w_fix
7.1.5.6 IJ28825m6b.201221.epkg.Z key_w_fix
7.1.5.6 IJ28825m6c.201221.epkg.Z key_w_fix
7.1.5.7 IJ28825m7a.201221.epkg.Z key_w_fix
7.1.5.7 IJ28825m7b.201221.epkg.Z key_w_fix
7.2.3.3 IJ28826m3a.201221.epkg.Z key_w_fix
7.2.3.4 IJ28826m4a.201221.epkg.Z key_w_fix
7.2.3.5 IJ28826m5a.201221.epkg.Z key_w_fix
7.2.4.0 IJ28827m0a.201222.epkg.Z key_w_fix
7.2.4.1 IJ28827m1a.201222.epkg.Z key_w_fix
7.2.4.2 IJ28827m2a.201222.epkg.Z key_w_fix
7.2.4.2 IJ28827m2b.201222.epkg.Z key_w_fix
7.2.4.2 IJ28827m2c.201222.epkg.Z key_w_fix
| 7.2.4.3 IJ28827m3a.210306.epkg.Z key_w_fix
7.2.5.0 IJ28828m1a.201222.epkg.Z key_w_fix
7.2.5.1 IJ28828m1a.201222.epkg.Z key_w_fix
Please note that the above table refers to AIX TL/SP level as
opposed to fileset level, i.e., 7.2.3.5 is AIX 7200-03-05.
NOTE: Multiple iFixes are provided for AIX 7100-05-05,
7100-05-06, 7100-05-07, and 7200-04-02.
IJ28825m5a is for AIX 7100-05-05 with bos.mp64 fileset level 7.1.5.35.
IJ28825m5b is for AIX 7100-05-05 with bos.mp64 fileset level 7.1.5.34.
IJ28825m6a is for AIX 7100-05-06 with bos.mp64 fileset level 7.1.5.38.
IJ28825m6b is for AIX 7100-05-06 with bos.mp64 fileset level 7.1.5.37.
IJ28825m6c is for AIX 7100-05-06 with bos.mp64 fileset level 7.1.5.36.
IJ28825m7a is for AIX 7100-05-07 with bos.mp64 fileset level 7.1.5.40.
IJ28825m7b is for AIX 7100-05-07 with bos.mp64 fileset level 7.1.5.39.
IJ28827m2a is for AIX 7200-04-02 with bos.mp64 fileset level 7.2.4.6.
IJ28827m2b is for AIX 7200-04-02 with bos.mp64 fileset level 7.2.4.4.
IJ28827m2c is for AIX 7200-04-02 with bos.mp64 fileset level 7.2.4.3.
Please reference the Affected Products and Version section above
for help with checking installed fileset levels.
VIOS Level Interim Fix (*.Z) KEY
-----------------------------------------------
3.1.0.20 IJ28826m3a.201221.epkg.Z key_w_fix
3.1.0.30 IJ28826m4a.201221.epkg.Z key_w_fix
3.1.0.40 IJ28826m5a.201221.epkg.Z key_w_fix
3.1.1.0 IJ28827m0a.201222.epkg.Z key_w_fix
3.1.1.10 IJ28827m1b.201222.epkg.Z key_w_fix
3.1.1.20 IJ28827m2c.201222.epkg.Z key_w_fix
3.1.1.21 IJ28827m2b.201222.epkg.Z key_w_fix
3.1.1.25 IJ28827m2a.201222.epkg.Z key_w_fix
| 3.1.1.30 IJ28827m3a.210306.epkg.Z key_w_fix
3.1.2.0 IJ28828m1a.201222.epkg.Z key_w_fix
3.1.2.10 IJ28828m1a.201222.epkg.Z key_w_fix
The fixes are cumulative and address previously issued
AIX/VIOS kernel security bulletins with respect to SP and TL,
which includes:
https://aix.software.ibm.com/aix/efixes/security/power9_advisory.asc
https://www.ibm.com/support/pages/node/6370729
To extract the fixes from the tar file:
tar xvf gencore_fix.tar
cd gencore_fix
Verify you have retrieved the fixes intact:
The checksums below were generated using the
"openssl dgst -sha256 [filename]" command as the following:
openssl dgst -sha256 filename KEY
-----------------------------------------------------------------------------------------------------
6d8482ef0decc18eb9cb37820ba1b8099cdf158523b6a95006cee1a081a48f83 IJ28825m5a.201221.epkg.Z key_w_csum
343e07de2e256b5439851da18ba3ea3a21dca3a98b55cba09306d46145c952de IJ28825m5b.201221.epkg.Z key_w_csum
71c903ff543d5c583d74330a48fdd60ab52d82ff8214407237ca9b8929d38d27 IJ28825m6a.201221.epkg.Z key_w_csum
e2798e2d78872870e153fad899b7f9b4c0eb0447b1068211050a91230989aa71 IJ28825m6b.201221.epkg.Z key_w_csum
3ac89e2e382cba3c440f37789f437a48be61f2bebcdf398e0a97ab2fa5dd20f7 IJ28825m6c.201221.epkg.Z key_w_csum
6bd374a44b0d571ce6628afb0ea163df493f942ddd618a616be24fa1839d7845 IJ28825m7a.201221.epkg.Z key_w_csum
0bce6ede7a2ea902d614eb892af533d90b4dfedf3a1d05f17b7ec1c21782fc38 IJ28825m7b.201221.epkg.Z key_w_csum
ec4f01c8bc31b61f9679be6d03d3ed7ac9713a4349b31c855eaf4b0f4b9cf377 IJ28826m3a.201221.epkg.Z key_w_csum
a3dae1d428ea866a7dab943285a4ebef8fa420451bd23bfeba919761fb4cd300 IJ28826m4a.201221.epkg.Z key_w_csum
8c6bb8caf628078c0387433ff978067280477d0b3ea3568102096cbf005a633c IJ28826m5a.201221.epkg.Z key_w_csum
5c9ad296cecb576dcef4631b75fa1987a9c856de07e466a5e1a6aa8529b7269f IJ28827m0a.201222.epkg.Z key_w_csum
8911ccd41e8926d247de9abc9da7387c1158a4b7606a945b2659dfaa95a6c8f6 IJ28827m1a.201222.epkg.Z key_w_csum
e6b977bef6e2d799b5b0ad0fd0a03c3b59922ee0a76ccaf414db97ca879e1329 IJ28827m1b.201222.epkg.Z key_w_csum
0637ffbb60a918da32548c3861fbfa381db04be375cf21d372efdef3711ca569 IJ28827m2a.201222.epkg.Z key_w_csum
50786a721811b2eff98fbb24c85ed9bb8977f44891d29114d8fe43d79c0fe10e IJ28827m2b.201222.epkg.Z key_w_csum
4c6b71538dedded55aeffe7451a02998885dcc80ca12b1fa7937d53ff1a26402 IJ28827m2c.201222.epkg.Z key_w_csum
| 321cd8cf7362d25c05948b0717029e54bcc7233002a5eaae1b30d5e88d5b5f13 IJ28827m3a.210306.epkg.Z key_w_csum
d8e107386c7eb45966ef9f3635f4e7253665c04795427f06a7e73a55b8847a54 IJ28828m1a.201222.epkg.Z key_w_csum
These sums should match exactly. The OpenSSL signatures in the tar
file and on this advisory can also be used to verify the
integrity of the fixes. If the sums or signatures cannot be
confirmed, contact IBM Support at
http://ibm.com/support/ and describe the discrepancy.
openssl dgst -sha1 -verify [pubkey_file] -signature [advisory_file].sig [advisory_file]
openssl dgst -sha1 -verify [pubkey_file] -signature [ifix_file].sig [ifix_file]
Published advisory OpenSSL signature file location:
http://aix.software.ibm.com/aix/efixes/security/gencore_advisory.asc.sig
https://aix.software.ibm.com/aix/efixes/security/gencore_advisory.asc.sig
ftp://aix.software.ibm.com/aix/efixes/security/gencore_advisory.asc.sig
C. FIX AND INTERIM FIX INSTALLATION
An LPAR system reboot is required to complete the iFix installation,
or Live Update may be used on AIX 7.2 to avoid a reboot.
If possible, it is recommended that a mksysb backup of the system
be created. Verify it is both bootable and readable before
proceeding.
To preview a fix installation:
installp -a -d fix_name -p all # where fix_name is the name of the
# fix package being previewed.
To install a fix package:
installp -a -d fix_name -X all # where fix_name is the name of the
# fix package being installed.
Interim fixes have had limited functional and regression
testing but not the full regression testing that takes place
for Service Packs; however, IBM does fully support them.
Interim fix management documentation can be found at:
http://www14.software.ibm.com/webapp/set2/sas/f/aix.efixmgmt/home.html
To preview an interim fix installation:
emgr -e ipkg_name -p # where ipkg_name is the name of the
# interim fix package being previewed.
To install an interim fix package:
emgr -e ipkg_name -X # where ipkg_name is the name of the
# interim fix package being installed.
WORKAROUNDS AND MITIGATIONS:
None.
===============================================================================
CONTACT US:
Note: Keywords labeled as KEY in this document are used for parsing
purposes.
If you would like to receive AIX Security Advisories via email,
please visit "My Notifications":
http://www.ibm.com/support/mynotifications
To view previously issued advisories, please visit:
http://www14.software.ibm.com/webapp/set2/subscriptions/onvdq
Contact IBM Support for questions related to this announcement:
http://ibm.com/support/
https://ibm.com/support/
To obtain the OpenSSL public key that can be used to verify the
signed advisories and ifixes:
Download the key from our web page:
ftp://ftp.software.ibm.com/systems/power/AIX/systems_p_os_aix_security_pubkey.txt
Please contact your local IBM AIX support center for any
assistance.
REFERENCES:
Complete CVSS v3 Guide: http://www.first.org/cvss/user-guide
On-line Calculator v3:
http://www.first.org/cvss/calculator/3.0
RELATED INFORMATION:
IBM Secure Engineering Web Portal
http://www.ibm.com/security/secure-engineering/bulletins.html
IBM Product Security Incident Response Blog
https://www.ibm.com/blogs/psirt/
Security Bulletin: Vulnerability in gencore affects AIX (CVE-2020-4887)
https://www.ibm.com/support/pages/node/6406022
ACKNOWLEDGEMENTS:
None.
CHANGE HISTORY:
First Issued: Tue Jan 19 16:15:13 CST 2021
| Updated: Tue Mar 30 09:09:39 CDT 2021
| Update: iFix now provided for AIX 7200-04-03 and VIOS 3.1.1.30.
===============================================================================
*The CVSS Environment Score is customer environment specific and will
ultimately impact the Overall CVSS Score. Customers can evaluate the impact
of this vulnerability in their environments by accessing the links in the
Reference section of this Security Bulletin.
Disclaimer
According to the Forum of Incident Response and Security Teams (FIRST), the
Common Vulnerability Scoring System (CVSS) is an “industry open standard
designed to convey vulnerability severity and help to determine urgency and
priority of response.” IBM PROVIDES THE CVSS SCORES “AS IS” WITHOUT WARRANTY
OF ANY KIND, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE. CUSTOMERS ARE RESPONSIBLE FOR ASSESSING THE IMPACT
OF ANY ACTUAL OR POTENTIAL SECURITY VULNERABILITY.
Related
CVSS2
Attack Vector
LOCAL
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:L/AC:L/Au:N/C:N/I:P/A:N
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
HIGH
Availability Impact
NONE
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
EPSS
Percentile
5.1%